We won't lose sleep... England not fretting over absence of skip Tindall

Martin Johnson does not want his England players to be kept awake at night by the prospect of their Grand Slam decider against Ireland in Dublin on Saturday, so he will be monitoring their sleeping patterns just in case.

The national team’s latest attempt to harness technology has led several members of the squad to volunteer to wear ‘watch-like’ devices to assess whether they are obtaining sufficient rest during the night.

This is what I want you to do: Martin Johnson and his England players are preparing for Saturday's showdown with Ireland

James Haskell is one of a group of players who agreed to take part in the trial, which started lastweek, as a means of judging whether energy levels are high enough to ensure optimum performance.

While the flanker could see the comic potential of the project, he nonetheless recognised it is another innovative approach — following the adoption of GPS tracking during matches — to giving England a possible edge.

Big miss: Mike Tindall is out of England's clash with Ireland in Dublin

In highlighting the increasing weight of scientific know-how at their disposal, Haskell said: ‘I’ve just taken off a watch-like thing that monitors my sleep patterns.

'I thought it might have been a listening device so I kept saying, “I love you Martin Johnson!”. I’m assured it’s just a sleep device, not a recording device!

‘We started using them last week before the Scotland game. It’s just another thing to see if it works and if it’s worth doing.’

The devices are being worn by the volunteers for most of the day and night — although not during training — and they measure the timing, quality and quantity of sleep by sensing body movement, with the principle being that the more still the person is, the better the quality of their sleep.

Haskell is a confident character so he is unlikely to be tossing and turning ahead of this weekend’s match. However, he is well aware of the magnitude of the occasion.

‘There are going to be nerves, there’s going to be fear, but there will be real excitement as well,’ he said. ‘This is a grand final against Ireland, in Ireland. We can’t leave anything in the tank.’

Johnson will on Thursday name a side featuring Matt Banahan at outside centre, David Strettle in his vacated place on the bench and Nick Easter as captain in the absence of Mike Tindall.

Volunteer: James Haskell in action for England against Scotland last weekend

As revealed in Sportsmail on Wednesday, Tindall’s ankle ligament strain has taken him out of contention and given Easter the chance to lead the team again. Strettle’s promotion to a place among the substitutes marks a significant revival for the 27-year-old.

He hasn’t played a Test since June 2008 and his last non-cap appearance for England was against New Zealand Maori in Napier last June, when his defensive lapses incensed the managements.

But he has performed well for Saracens after a summer move from Harlequins and as Delon Armitage has only just finished serving a ban, his time has come.

Meanwhile, England are awaiting updates from World Cup officials about the revised location of their training base and two pool matches in New Zealand, after the IRB confirmed that games allocated to Christchurch would be moved because of earthquake damage.

Johnson’s men were due to play Pool B matches against Argentina and Georgia in the city, as well as a possible quarter-final game.

The latter tie will now take place in Auckland, but the RFU are standing by for further guidance on the other matches.

Johnson said: ‘We feel for the people of Christchurch who are still suffering following the tragic earthquake, but we accept this is the right decision.

'We are working closely with Rugby World Cup Ltd to understand the options for our pool games and what that means for us in terms of a training base.’